• Molecules and Cells
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• v.22 no.1
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• pp.51-57
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• 2006

Haloperidol is a classical neuroleptic drug that is still in clinical use and can lead to abnormal motor activity following repeated administration. However, there is little knowledge of how it triggers neuronal impairment. In this study, we report that it induced calcium ion influx via L-type calcium channels and that the elevation of calcium ions induced by haloperidol appeared to render hippocampal cells more susceptible to oxidative stress. Indeed, the level of cytotoxic reactive oxygen species (ROS) and the expression of pro-apoptotic Bax increased in response to oxidative stress in haloperidol-treated cells, and these effects were inhibited by verapamil, a specific L-type calcium channel blocker, but not by the T-type calcium channel blocker, mibefradil. These findings indicate that haloperidol induces calcium ion influx via L-type calcium channels and that this calcium influx influences neuronal fate.

• Journal of Life Science
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• v.21 no.8
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• pp.1076-1082
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• 2011

Microtubule-based kinesin motor proteins are used for long-range vesicular transport. KIF5s (KIF5A, KIF5B and KIF5C) mediate the transport of various membranous vesicles along microtubules, but the mechanism behind how they recognize and bind to a specific cargo has not yet been completely elucidated. To identify the interaction protein for KIF5B, yeast two-hybrid screening was performed and a specific interaction with the unconventional myosin Myo9b, an actin-based vesicle transport motor, was found. The GTPase-activating protein (GAP) domain of Myo9s was essential for interaction with KIF5B in the yeast two-hybrid assay. Myo9b bound to the carboxyl-terminal region of KIF5B and to other KIF5 members. In addition, glutathione S-transferase (GST) pull-downs showed that Myo9s specifically interact to the complete Kinesin-I complex. An antibody to KIF5B specifically co-immunoprecipitated KIF5B associated with Myo9s from mouse brain extracts. These results suggest that kinesin-I motor protein interacts directly with actin-based motor proteins in the cell.

• YAKHAK HOEJI
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• v.55 no.5
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• pp.385-390
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• 2011

Bee venom (BV), which is extracted from honeybees, has been used in traditional Korean medical therapy. Glutamate-mediated excitotoxicity contributes to neuronal death in neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) or Alzheimer's disease (AD). This study is to investigate the effect of BV on glutamate-induced neurotoxicity on NSC-34 motor neuron cells. To determine the viability of motor neuronal cells, we performed with MTT assays in glutamate-treated NSC-34 cell with BV or without. For the measurement of oxidative stress, DCF assay was used in glutamate-treated NSC-34 motor neuronal cells with BV or without. To investigate the molecular mechanism of BV against glutamate-mediated neurotoxicity in NSC-34 cells, western blot analysis was used. Glutamate significantly decreased cell viability by glutamate dose- or treatment time-dependent manner in NSC-34 cells. However, BV pre-treatment dramatically inhibited glutamate-induced neuronal cell death. Furthermore, we found that BV increased the expression of Bcl-2 protein that is anti-apoptotic protein and reduced the generation of oxidative stress. BV has a neuroprotective role against glutamate neurotoxicity by an increase of anti-apoptotic protein. It suggests that BV may be useful for the reduction of neuronal cell death in neuronal disease models.

• BMB Reports
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• v.29 no.2
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• pp.151-155
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• 1996

To swimming motor neurons (SMNs) of Polyorchis penicillatus, a hydrozoan medusae, dopamine (DA) acts as an inhibitory neurotransmitter by hyperpolarizing its membrane potential and decreasing its firing rate as well. Such an inhibitory action of DA is caused by an increased permeability to potassium (K) ions. To investigate whether voltage-gated K channels are directly responsible for the membrane hyperpolarization induced by DA, we employed whole-cell voltage clamp configuration. One ${\mu}M$ DA applied to SMNs increased the peak and rear values of voltage-gated K currents by 37 and 54%, respectively, in a reversible manner. Combined with subtraction analysis, this result suggests that the outflux of K ions by DA in SMNs occurs mainly through rectifier-like K channels.

• Investigative Magnetic Resonance Imaging
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• v.16 no.2
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• pp.136-141
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• 2012

Purpose : To investigate the pharmacologic modulation of motor task-dependent physiologic responses by antiplatelet agent, clopidogrel, during hand motor tasks in healthy subjects. Materials and Methods: Ten healthy, right-handed subjects underwent three functional magnetic resonance (fMRI) sessions: one before drug administration, one after high dose drug administration and one after reaching drug steady state. For the motor task fMRI, finger flexion-extension movements were performed. Blood oxygenation level dependent (BOLD) contrast was collected for each subject using a 3.0 T VHi (GE Healthcare, Milwaukee, USA) scanner. $T2^*$-weighted echo planar imaging was used for fMRI acquisition. The fMRI data processing and statistical analyses were carried out using SPM2. Results: Second-level analysis revealed significant increases in the extent of activation in the contralateral motor cortex including primary motor area (M1) after drug administration. The number of activated voxels in motor cortex was 173 without drug administration and the number increased to 1049 for high dose condition and 673 for steady-state condition respectively. However, there was no significant difference in the magnitude of BOLD signal change in terms of peak T value. Conclusion: The current results suggest that cerebral motor activity can be modulated by clopidogrel in healthy subjects and that fMRI is highly senstive to evidence such changes.

• Molecules and Cells
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• v.41 no.1
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• pp.45-49
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• 2018

Autophagy is a lysosome-dependent degradation process that is essential for maintaining cellular homeostasis. In recent years, more studies have focused on the late stages of autophagy. Our group discovered and studied the terminal step of autophagy, namely autophagic lysosome reformation (ALR). ALR is the process that regenerates functional lysosomes from autolysosomes, thus maintaining lysosome homeostasis. ALR involves clathrin-mediated membrane budding from autolysosomes, elongation of membrane tubules along microtubules with the pulling force provided by the motor protein KIF5B, proto-lysosome scission by dynamin 2, and finally maturation of proto-lysosomes to functional lysosomes. In this review, we will summarize progress in unveiling the molecular mechanisms underlying ALR and its potential pathophysiological roles.

• PNF and Movement
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• v.2 no.1
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• pp.35-47
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• 2004

Purpose : The purpose of this article was to review the literature on contractile properties of skeletal muscle with reference to its molecular and functional diversity. Method : This review outlines scientific findings regarding different contractile properties in skeletal muscle fibers, and discusses their involvement in functional diversity. Result & Conclusions: Muscle fibers possess distinct mechanical and energetic properties. Myosis, one of the primary contractile muscle proteins, displays structural, functional variability and plays the role of the molecular motor of muscle contraction. Muscle satellite cells are normally mitotically quiescent, but initiate proliferation and give rise to daughter myogenic precursor cells as required for the postnatal growth and regeneration of adult muscle. Passive extensibility is an important component of total muscle function because it allows for the maximal length of skeletal muscles. Proprioceptive neuromuscular facilitation(PNF) stretching can help to restore or improve flexibility and coordination, thereby improving overall muscle function.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.11
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• pp.47-55
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• 1993

This paper is to design an autobalancing system based-on microprocessor for hemodiafiltration (HDF) system. The proposed system consist of motor control part, thermostatic control part, alarm system and electronic scale which ar automatically controlled by microprocessor. Conventional hemodialysis system can not remove medium molecular articles but hemodialysis system with the proposed system can remove and infuse substitute to the patient. This system can be easily interfaced with any other conventional HD system. The results obtained from performance evaluation of the proposed system are suitable for clinical supporting system.

• Journal of Life Science
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• v.21 no.9
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• pp.1226-1233
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• 2011

In neurons, kinesin is the molecular motor that transport cargos along microtubules. KIF5s (alias kinesin-I), are heterotetrameric motor conveying cargos, but the mechanism as to how they recognize and bind to a specific cargos has not yet been completely elucidated. To identify the interaction proteins for KIF5C, yeast two-hybrid screening was performed, and specific interaction with the $\underline{S}$am68-$\underline{l}$ike $\underline{m}$ammalian protein $\underline{2}$ (SLM-2), a member of the $\underline{s}$ignal $\underline{t}$ransducers and $\underline{a}$ctivators of $\underline{R}$NA (STAR) family of RNA processing proteins, was found. SLM-2 bound to the carboxyl (C)-terminal region of KIF5C and to other KIF5 members. The C-terminal domain of Sam68, SLM-1, SLM-2 was essential for interaction with KIF5C in the yeast two-hybrid assay. In addition, glutathione S-transferase (GST) pull-downs showed that SAM68, SLM-1, and SLM-2 specifically interacted to Kinesin-I complex. An antibody to SAM68 specifically co-immunoprecipitated SAM68 associated with KIF5s and coprecipitated with a specific set of mRNA. These results suggest that Kinesin-I motor protein transports RNA-associated protein complex in cells.

• Macromolecular Research
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• v.12 no.1
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• pp.112-118
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• 2004

With the goal of enhancing the creep resistance of ultra-high molecular weight polyethylene (UHMWPE), we performed gamma irradiation and post-irradiation annealing at a low temperature, and investigated the crystalline structures and mechanical properties of the samples. Electron spin resonance spectra reveal that most of the residual radicals are stabilized by annealing at 100$^{\circ}C$ for 72 h under vacuum. Both the melting temperature and crystallinity increase after increasing the dose and by post-irradiation annealing. When irradiated with the same dose, the quenched sample having a higher amorphous fraction exhibits a lower swell ratio than does the slow-cooled sample. The measured tensile properties correlate well to the crystalline structure of the irradiated and annealed samples. For enhancing creep resistance, high crystallinity appears to be more critical than a high degree of crosslinking.